Aguero signs one-year contract extension at Man City

Chelsea have been delayed on their return from Greece following the 1-0 win over PAOK Salonika in the Europa League on Thursday.

A scheduled flight from Thessaloniki to London was cancelled after weather warnings, meaning Chelsea will return to Cobham on Friday afternoon -- less than 48 hours before they are due to face West Ham United in the Premier League on Sunday.

Sources told ESPN FC that the club were aware of the situation prior to kick-off against PAOK, where Chelsea made a winning start to their Europa League campaign thanks to Willian's seventh-minute goal.

But that will be little consolation to Sarri, who made only five changes to his starting XI for the PAOK game and raised concerns about the scheduling of the West Ham game in his news conference after the victory.

Asked if he will continue to field a significant number of regular starters in the Europa League, Sarri said: "I don't know, because for an English team, the Europa League is a difficult competition.

"In Italy, you can play on a Monday night, but not in England. For us, it is very difficult. I don't know in the future. It is not a big problem now. We have only played six matches. In the future, it might be tough."

Eden Hazard, Mateo Kovacic, David Luiz and Emerson Palmieri will not be affected by Chelsea's delayed return as all four were left out of the travelling party.